Inflatable cuffs are provided on various types of catheters and medical tubes to close-off a body passageway between the tube and the sidewalls of the passageway. For example, endotracheal and tracheotomy tubes may be provided with cuffs to close off the trachea of a patient while supplying air or other gas to the lungs. It has been common practice to connect a valve in fluid communication with the cuff that is constructed to receive the tip of a syringe barrel. A piston slidable in the barrel forces air through the tip and valve to inflate the cuff within the passageway of the patient. Generally, when the barrel tip is inserted into the valve, the valve opens, and when the tip is removed, the valve closes to maintain the cuff inflated. A pilot or pressure indicating balloon is often connected to the cuff to provide a visual indication of the pressure condition within the cuff.
Such cuff inflation systems have certain disadvantages or problems associated with them. For example, when it is desired to inflate the cuff, a syringe must be located, unpackaged, and the barrel tip inserted into the valve, with such insertion generally requiring the use of both hands. The syringe must then be removed from the valve to allow the valve to close. Sometimes adjustment of the pressure within the cuff is required because of an increase or decrease in the cuff pressure as result of gas permeating the cuff or because of an air leak in the inflation system. Each time the pressure is adjusted, a syringe must be located and the tip again inserted into the valve to adjust the air pressure in the cuff, and then the syringe is again removed from the valve. Thus, use of the above type of syringe and valve is somewhat complicated and generally involves a considerable amount of time to use. Also, there is a chance of misplacing the syringe or of having difficulty in finding a syringe when needed.
In U.S. Pat. Nos. 3,707,146 and 3,841,319, hand pumps in the form of elastomeric bulbs are employed to inflate the tube cuffs. A pressure indicating balloon is also used in the latter patent. The cuff inflation systems of these patents do not require a separate syringe that must be connected and disconnected each time air is injected into or ejected from the cuff. However, such pumps generally include relatively complicated and expensive rotary valves.
Such rotary valves generally employ metal valve parts and a vent arrangement at the valve. Also, a one-way intake valve such as a ball valve, is generally required at the end of the pump bulb. Since medical tubes or catheters are generally of the "disposable" type, that is, intended for single-use or one patient only, and then discarded, hand pumps of this type would cause the cost of the medical to be exceedingly high.